1. Field of the Invention
The present invention relates to a load display device for a machine tool, configured to simultaneously display the sizes and directions of loads on axes of a machine tool, in the form of vectors, on a tool trajectory during machining displayed on a display screen, thereby enabling visual recognition of changes in size and direction of loads on a tool path.
2. Description of the Related Art
In a numerical controller having a machine state monitoring function, the state of the numerical controller can be recorded at an arbitrary timing during operation of a machining program. If an abnormal load on a motor is detected in a numerical controller capable of monitoring a machine state, the machine state at that time is recorded to be used to clear up the cause of the abnormal load.
Japanese Patent Application Laid-Open No. 2011-22688 discloses a method of displaying the position of a tool center point in association with a position error during machining. In this method, a corresponding point between a tool trajectory and a time-base position of waveform data for each axis is visually captured. Further, Japanese Patent Application Laid-Open No. 2009-116745 discloses a method of using load information, in which a simulation of machining is displayed in association with the load information.
In some cases, a machine or workpiece may be damaged as a spindle is impacted during machining by means of the numerical controller. To investigate the cause, the state of the machine should be checked based on machine state monitoring. However, actual occurrence of an incidence cannot be easily recognized by only displaying instantaneous numerical values indicative of the state of the machine, so that it is difficult to locate the cause. Even if the machine state is displayed in time series, on the other hand, it is hard to grasp the details of the machining based on this data alone.